中文摘要：

以有限元分析软件ANSYS为平台，基于非线性板壳有限元分析理论，对轻型门式刚架中H型钢楔形薄壁梁的相关屈曲性能进行大挠度弹塑性分析。用Shell 181单元对轻型门式刚架中H型钢楔形薄壁梁进行离散。考虑初始几何缺陷和残余应力的影响，对其进行全过程跟踪分析，从而对其相关屈曲性能进行深入的研究。从荷载一位移曲线、承载力、变形的发展和塑性区的分布等方面入手。对影响相关屈曲性能的因素（腹板高厚比、翼缘宽厚比、跨度、楔率等）进行系统的分析和研究，并与现行规范进行比较，得到一些有价值的结论。

英文摘要：

Based on the finite element method, the interactive buckling of tapered H-section steel beams used in portal frame structures are analyzed by ANSYS, in which geometric and material non-linearity are considered. The H-section tapered beams with thin web are dispersed by Shell 181 element and analyzed considering the geometric initial imperfection and the residual stress in the whole course. According to the load-deflection curves obtained, ultimate load-carrying capacity, deformation and the area of plasticity etc, the geometric parameters are analyzed systematically, which include web width-thickness ratio,flange width-thickness ratio , span and web tapering ratio etc. The interactive buckling of tapered H-section steel beams is discussed. By comparing the results obtained from the method with those of current Chinese technical specification, some valuable conclusions are drawn.